Hand portable power unit



July 20, 1965 A. H. KENT HAND PORTABLE POWER UNIT 2 Sheets-Sheet l Filed Aug. 6. 1962 INVENTOR ALLEN H. KENT BYmL-bwuk,

ATTO FZ N EYS Ilull July 20, 1965 A. H. KENT 3,196,298

HAND PORTABLE POWER UNIT Filed Aug. 6. 1962 2 Sheets-Sheet 2 ll Q INVENTOR ALLEN H. KENT BY @auffrgm ATTORNEYS United States Patent O 3,196,298 HAND PORTABLE POWER UNIT Allen H. Kent, New York, NY., assigner to Landers, Frary & Clark, New Britain, Conn., a corporation of Connecticut Filed Aug. 6, 1962, Ser. No. 215,161 2 Claims. (Cl. S10-S0) This invention involves improvements in hand portable power tools particularly those energized with dry batteries.

One object of the invention is to provide a tool of this type which is adapted to operate various types of tools or implements specically for oscillatory operation, such as for example, a toothbrush.

A further object of the invention is to provide a tool of this type which is sealed against the entrance of moisture so that for use of such a toothbrush it can safely be used around Water and even immersed in it without damage.

Another object of the invention is to provide a structural assembly of this type in which substantially all of the parts are mounted on a pair of rods by means of which they can be clamped into a unit and by means of which the housing can be held in place.

A more detailed object is to provide a control circuit arrangement in which said rods form part of the circuit.

Other and more detailed objects of the invention will be apparent from the following description of the embodiment of the inven-tion illustrated in the attached drawings.

In the drawings there is shown in FIGURE 1 a longitudinal, central, cross-sectional view of the structure of the invention with some parts broken away to facilitate illustration;

FIGURE 2 is a View of the righthand end of the device as illustrated in FIG. 1, turned, however, through an angle of 90 degrees on its longitudinal axis;

FIGURE 3 is a cross-sectional view taken on the line 3 3 of FIG. 2;

FIGURE 4 is a cross-sectional view taken on the line 4-4 of FIG. 2;

FIGURE 5 is an exploded perspective detailed view of the battery unit; and

FIGURE 6 is a similar view of the lefthand end of the battery unit viewed from the opposite side.

As illustrated the device includes a casing of which the tubular sleeve 10 is a part. This sleeve is of circular cross-section, open at both ends, and may be made of any suitable material including metals and plastics. One end of this tube is closed by means of a nose piece 12, which is preferably molded of a rugged waterbound plastic. The nose piece has an annular seat at one end proportioned so that it may slip snugly into the end of the sleeve 10 and a watertight joint is assured by the use of an O-seal ring 14.

The backbone of the structure is a pair of elongated rods 16 and 18 which have shoulders formed by annular enlargements 12a and 18a adjacent the base of the inwardly offset ends 16h and 18h of the rods. These rods pass through washers 20 and 22 which rest upon bifurcated internal radial projections 16e and 16d molded in the nose piece, see particularly FIG. 3.

At 24 is a disc of suitable material which is offset at the inner end of the nose piece 12, which can also be made of any suitable material, including metal, through which the rods pass, see FIG. l. When made of metal an insulating sleeve 26 is threaded on the rod 16 so as to lie in the hole of the disc 24 to insulate the rod therefrom.

The motor includes a permanent magnet eld structure 28 within which is axially positioned the wound rotor 30. This rotor is mounted for rotation in a bearing 32 which is mounted inthe disc 24 in an O-seal ring 34. End thrust ice washers 36 are interposed between the rotor and the bearing `assembly 32. The motor unit includes a second disc 38, which when made of metal, will have an insulating bushing 39 in the aperture through which the rotor 16 passes. Rod 18 also passes through this disc and between it and the disc 24 `is .seated an enclosing sleeve 49 surrounding the eld and rotor of the motor. The other end of the rotor shaft is supported on disc 38 by means of a bearing assembly 40, which in turn is mounted in an O-seal ring 42. At 44 is the commutator for the motor rotor or armature. As can be seen in FIGS. 1 and 5, the magnetic field structure 28 has a pair of diametrically opposed surface longitudinal grooves in which the rods 16 and 18 rest, but in the case of the rotor 16, an insulating sleeve 49 is provided to insulate the rod from the magnet 28.

The power transmission unit includes a pinion 47 secured to the end of the armature shaft and meshing with the part 48 of a double pinion. This compound pinion is freely rotatable on the end 50 of the shaft 60, see FIG. 2. The teeth 52 of this pinion mesh with a gear 54 which is rotatably mounted on a shaft 56 which is also supported at the disc 24, see FIG. 2. On the outer face of the pinion 54 is a cam button 56 Which operates in the bifurcated end of a lever 58, see FIG. 4. This lever is secured to the shaft 66 which is journaled at one end in a suitable bushing 62 mounted in the nose piece 12. The other end of the shaft 60 of course is journaled for movement by its reduced end 50 in the disc 24. The shaft 60 passes through a sealing washer 64 mounted in a recess in the nose piece 12, which is closed by a cup shaped member 66, which can be snapped into place. The bearing bushing 62 can be molded of a suitable plastic such as for example nylon and can be longitudinally split so that it can be compressed sufficiently tio seat it in the related passage of the nose piece 12, as shown in FIG. 1. The closure 66 is likewise molded of a suitable plastic so that its mounting prongs 67 can be snapped into the recess in the end of the nose piece. At 68 is diagrammatically illustrated the outlet which can be detachably mounted on the exposed end of the shaft 60 and which for example can be the stem of a toothbrush.

At 70, see FIGS. 1, 2 and 3, is a T-shaped switch-blade, the yhead of which has its ends shaped, as shown in FIG. 3, so that it can be moved into and out of contact with the rods 16 and 18. The end 70 of the stern of the T is offset so that it can be clamped behind and supported by the flanged end of the bushing `62, see FIG. 2. Slidably mounted in the internal rib 12a of the nose piece is a pin 72 which bears at one end on the contact finger 70 and is eugaged at the other end by the cam 78a formed integral with the switch button 78. As shown in FIG. 2 the side of the nose -piece is provided with a recess in which the cam 78a is mounted. The cam 78a, lsee FIG. 3, is an integral part of the switch button 78 and formed with a T-shaped head, so that a mounting spring 76 can embrace it a shown from the sides. Referring to FIG. 2, it will be seen that the ends ofthe spring 76 normally flare outwardly and are therefore compressed when they are forced into the opening of the recess. When the parts are in place the spring end-s snap outwardly against a pair of shoulders 80 and 82 to hold the butt-on in place. The point 72 is sealed by the O-seal ring 74. At this point it may be noted that when taking the structure apart the spring 76 can be released by means of the pin passed through a hole, not shown, in the nose piece 12 to disengage the associated ared ends of the spring from the shoulder 80. The switch button and the spring can then be removed.

As shown in FIG. 2 the disc 38 is provided with a pair of aligned radial holes of square cross-section in which the metal bushing 84 and 86 are mounted. These bushings provide housings for the springs 88 and 90 which force the square brushes 92 and 94 into contact with the comrnutator 44. j

Also threaded on the rods 16 and 13 is an insulating disc 96 which is provided on the periphery with the diametrically opposed rectangular notches 96a Vand 95d with a rectangular aperture 96e and a cutout 9611 having circular andradial portions. The circular portion lits around the post 38a formed on the ldisc 38. At 98 and 100, 4see FIGS. 2 and 5, are a pair of specially shaped connectors. The connector 98 has an offset end 93a which `in the assembly overlies the end of the spring land makes contact therewith. The :other end 9% is upstanding and terminates in a contact. Thisend of the contact 9S will partially lie in the opening 96h when the parts are assembled, see FIG. 1. Contact 100 is shaped so that the rod 16 passes through it and also so that its offset end 1Mb can extend into the rectangular opening 96e. The other end 11Min of the contact falls in the notch 96d.

The battery support and connector comprises an assembly consisting of the discs 1112 and 104 connected by four equal -circumferentially spaced metal channels 166, 1%, 110, 112. These channels, "as shown, have tubes which lie in apertures in the discs and are bent overto form a spoollike assembly. The parts are proportioned so that dry cells of proper size can be positioned between adjacent pairs of channels.' These channels have lateral projections lying on the inner faces of the discs 1112 and 1114 so that four batteries can be placed therein to connect them in series. One terminal of this series connections will contact the end 9811 of the connector 9S 'which is exposed through the opening 112a in the disc 192. As shown in FIG. 1 the disc 1112 of the battery support also tits over the boss 38a. The other connector 111th electrically connects the rod 16 with the spring S3, see FIG. 2l The other terminal of the series connected batteries is connected byrneans of the jumper 114 mounted on the disc 104 with the rod 18.

Referring to FIG. 1, there is shown a disc 116 having a ring of insulating material 118 on one face. The rods 16 and 18 pass through apertures in the disc 116 which are lined with the bearings 120 and 122 to insulate the rods from short circuit by the disc 116.` Another insulating ring 117 lies on the other face of the disc 116. The ends of the ribs 16 and 18 project through this assembly and have threaded thereon nuts'124 and 126 by means of which all parts of the entire assembly with the exception of the housing sleeve 1) and the closure cap 128 are clamped together as a unit. Reference will be further made to this point subsequently.

The closure 123 can be molded of suitable plastic and has centrally mounted thereon a thumbscrew 139, the threaded end of which engages in a th-readed aperture in the disc 116. The inner face and the finger piece of the thumbscrew all recess in which a sealing washer 132 is mounted for engagement with an annular rib on the closure' `disc 12.8 surrounding the opening through which the end of the thumb screwv passes. It will be seen'that since the enlargements 16a and 13a on the rods are caught behind the internal shoulders 16e and 18c,gsee FIG. 3, and all of the internal parts are locked thereon by means of the nuts 124 and 126, when the thumb screw is drawn up tight the sleeve 10 will be clamped between it and the nose piece into a rigid, firm assembly. Suicient pressure can be brought to bear between the adjacent end of the sleeve 10 and the closure disc 128 so as to make the housing watertight as this point. The shoulder projection on the closure nut can be dimensioned to provide a tight press litV with the end of the sleeve 11111. Y

From the above description it will be seen that a very compact, easily assembled, device is provided. With reference to assembly, one of the important features of this invention is ease of assembly. The nose piece 12 can be mounted-upright in a tixture with .the shaft 6i) already mounted in place. T he washers Ztl and 22 are slipped onto the rods and the rods are seated in the lugs 16C and 18e. The disc 2d is then slipped onto the rods which serves to lock them in the nose piece. The bearing 26 is applied, or it may be cemented in the aperture of theV disc 2li.' The field magnet ring 28 is positioned on the rods with the bushing 49 in place and the armature liti is positioned with` its bearing in the O-seal ring 34. The disc 33 is then positioned over the bearing assemblyd on the other end of the armature shaft with the bearing 39 in place, the sleevev 46 having been seated on the disc Z4 so as to be clamped behind the discs 24 and 3d. The disc 96 is then yslipped onto the rods followed by the battery holder assembly. Disc 116 is then positioned and locked on the rods. It will be apparent7 of course, that the pinion 47 will be attached to the end of the 'armature shaft after it has been positioned in the disc 2d.

As an alternative it may be noted that the parts of the motor could form a sub-assembly, that is the parts could be assembled and then slipped as a unit onto the rods. The assembly is then completed by positioning the sleeve 1t), applying the cap 128'and tightening up the thumb screw 130. The switch button is easily assembled by just pushing it into the nose piece so that the flared ends of the spring 76 seat on the shoulders tid and 32.

t will be apparent to those skilled in the art that various details of this structure can be changed without departing from the` novel subject matter herein disclosed. It is intended, therefore, that the `scope rof protection afforded hereby bedetermined by the appended claims.

What is claimed is:

1. A hand portable power tool comprising a motor unit, a nose pie-ce housing `and a power gear transmission unit, a battery supporting unit having current output terminals, a

pair of rods connecting all of said units into a unitary aligned structure, means including a contact nger in lsaid nose piece housing for connecting said output terminals in ,series with the motor of said motor unit through said rods,

v References @Cited bythe Examiner Y UNITED STATES PATENTS 2,339,829 l/44 Youhouse S10- 50 2,657,321 10/53 Sniitihson S10-5() 2,730,635 1/56 McCabe 310-50 2,987,636 6/61 epson 310-50 3,034,376 5/62 Gonzalez 310--50 3,035,191 5/62 Kent 310-50 MILTON O. HIRSHFELD, Primary Examiner. Y 

1. A HAND PORTABLE POWER TOOL COMPRISING A MOTOR UNIT, A NOSE PIECE HOUSING AND A POWER GEAR TRANSMISSION UNIT, A BATTERY SUPPORTING UNIT HAVING CURRENT OUTPUT TERMINALS, A PAIR OF RODS CONNECTING ALL OF SAID UNITS INTO A UNITARY ALIGNED STRUCTURE, MEANS INCLUDING A CONTACT FINGER IN SAID NOSE PIECE HOUSING FOR CONNECTING SAID OUTPUT TERMINALS IN SERIES WITH THE MOTOR OF SAID MOTOR UNIT THROUGH SAID RODS, A CASING ENCLOSING SAID UNITARY ALIGNED STRUCTURE CLOSED AT ONE END BY SAID NOSE PIECE HOUSING, AND A DETACHABLE CLOSURE FOR THE OTHER END OF SAID CASING SEATED THEREON. 